The present invention relates to a waste fire suppression control device which is attached to the base of a conventional garbage chute typically used in high rise buildings. More specifically, the present invention comprises and incorporates a sequence of two control doors which prevent smoke and fire entering the chute system in the event of a fire in the dumpster area. One door is a main control door which is biased towards a closed position separating the exhaust end of the chute from the dumpster below and which opens only in response to a pre-determined release force or weight exerted on the top surface of the door. The other door is a closing plate which during normal operation of the device is held in an open position and which can be deployed either manually or automatically to close the chute. Both doors act as barriers against smoke and fire. The second door ensures that a barrier will be in place in the event that the first door becomes in operable for this purpose. The present invention further integrates a system of conventional sprinklers which flood the device and dumpster below with water. Garbage chutes typically consist of a vertical tube having an intake opening at each floor and are used in most high rise buildings to convey garbage from the upper floors of the building to the basement where it is collected in a dumpster for disposal. In most jurisdictions, fire codes mandate that chute systems have heat activated control doors at the base thereof to prevent smoke and fire from travelling up the chute system in the event of a fire in the dumpster area.
Various control doors for attachment to the discharge end of typical garbage chutes are known. The "A" and "CA" rolling type doors attach to the exhaust end of the garbage chute. Both the "A" and the "CA" designs comprise an inclined door which is held open under normal operating conditions by a fusible link. Each type of door has wheels attached thereto which fit into corresponding tracks which form part of the support frame. When the fusible link fuses at the specified temperature the door rolls shut under the force of gravity.
Another door adapted for use at the bottom of garbage chutes is the "accordion" type door which during normal operations is held open by a spring loaded fusible link assembly. When the link fuses, the door is released and slides along tracks to form a barrier between the dumpster and the chute system. The "accordion" type door is most commonly used in association with chute which discharge directly into a bin or compactor. The fusible links which deploy the prior art doors described above are typically activated at a temperature of about 165 F (74 C).
It should be emphasized that the above mentioned prior art doors are all held open during normal operations. The "A" and "CA" rolling type doors and the "accordion" type door are intended only to provide basic smoke and fire protection and are not designed to perform as a shut-off gate. Because these types of doors are held open during normal operation, the discharge area at the exhaust end of the chute must be kept relatively airtight or under slight negative pressure to minimize the chimney or stack effect. The chimney effect associated with chute systems in high rise buildings tends to draw smoke and toxic fumes, as well as air borne bacteria, up into the chute at a rates up to 40 kph. The smoke, fumes, or contaminated air can then be blown out through the chute intake openings at each floor when a given intake door is opened or stuck open for some other reason.
The "A", "CA", and "accordion" type doors do not operate as a complete seal to prevent smoke and fumes from entering the chute. As well, proper deployment of the prior art doors depends on the tracks on which they slide being free of garbage and not being damaged. These types of doors respond only after the fusible link holding the door in the open position has fused at 165 F. Even if properly deployed the prior art doors do not effectively seal off the chute.
The present invention overcomes the disadvantages associated with the prior art by closing off and sealing the garbage chute during normal operation of the device using a main control door which is biased towards a closed position. The main control door opens to permit garbage to fall into a dumpster positioned below the exhaust opening of the device only when the weight or force of the garbage on the top surface of the door is greater than a pre-determined release force. The main control door automatically returns to its original closed position after opening.
The present invention further overcomes the disadvantages associated with the prior art by means of a second door which acts as a closing plate which can be deployed either manually or automatically to form an additional and effective barrier to prevent smoke and fumes from travelling up the chute. The automatic release of the closing plate is controlled by two independent fusible links each of which is capable of deploying the closing plate. In both the automatic and manual modes, a conventional heat activated sprinkler system operates simultaneously to flood the apparatus with water further ensuring a tight seal at the edges surrounding each door.
By closing and sealing the base of the chute during normal operation the stack effect is minimized and in the event of a fire in the dumpster smoke and fire are contained within the dumpster room. The closing plate and sprinkler system provide additional safety features to prevent smoke and fire from entering the chute system and reaching the upper floors of the building. The closing plate and sprinkler system are automatically activated by conventional fusible links at a temperature of 135 F as opposed to 165 F. By reacting at a lower temperature, the device can begin containing and counteracting fire and smoke more quickly, in turn potentially minimizing costly damage.